There are various woodworking methods employed in the construction of buildings with wooden members. As shown in FIG. 5 to 7, a so called "metal fit" joint is illustrated using a metal plate connector A having a pair of metal protrusions 63 and 64. The "metal fit" joint is used for connecting a horizontal wooden member to a vertical wooden member having a special slot to be discussed below. The metal protrusions 63 and 64 are provided with end plates 65 and 66, respectively. The end plates 65 and 66 can be attached, for example, by welding. The metal plate 60 is provided with a hole 62 and a U-shaped slot 61 for connecting the metal plate to the horizontal wooden member using bolts. A metal fitting B defined by a metal plate 70 having a slot 71 and four holes 72 is used as a backing plate for the horizontal wooden member.
The method of forming the joint is illustrated in FIGS. 9 through 13. The horizontal member or beam 90 has holes 91 and 92 which corresponds to the slot 61 and the hole 62 in plate A. The beam 90 also has an end slit at its end (not shown). The holes 81, 82 are drilled into the vertical member or column 80. The metal protrusions arms 63 and 64 having welded metal end plates 65 and 66 are inserted into the previously drilled holes 81 and 82 in the column 80, as shown in FIG. 9.
Once the metal end plates 65 and 66 are fully fitted into the drilled holes 81 and 82, the metal plate connector A is hit downwardly with an appropriate tool to set the metal plate connector A firmly in the column 80, as shown in FIG. 10.
As shown in FIG. 11, a pin 93 having a D-pin shaped cross section is inserted into the previously drilled hole 91 in the beam 90. The beam 90 is then moved in the direction of the arrow all the way so that the end grain of the beam 90 meets the column 80 completely.
The beam 90 is then pushed down from its upper side until the pin 93 registers with the bottom of slot 61, as shown in FIG. 12. The beam 90 is further forced downwardly with appropriate pressure, and the pin 94 is inserted through the hole 92 in the beam 90, and through hole 62 of the plate A. Nuts are threaded onto and tightened on the pins 93 and 94.
In order to use the metal plate connector A to connect the beam 90 to the column 80, it is necessary to provide joints 110 and 120 in the column 80.
The joints 110 and 120 are made by first drilling holes 81 and 82 in the column 80. Top plan view of the holes 81 and 82 are shown in FIG. 14. Here, the pair of holes 81 and 82 are drilled in the wood member 100 with a drill bit. Secondly, smaller width slots 112 and 122 are made extending from the holes 81 and 82 with a rotary cutting bit. Thirdly, larger width slots 113 and 123 are made extending from the holes 81 and 82 with a different rotary bit.
Thus, the holes 81 and 82 having cylinder shaped cross sections, slots 112, 122 have rectangular shaped cross sections, and slots 113 and 123 have rectangular shaped cross sections. The slots 113 and 123 are positioned at a lower side of the slits 112, 122.
In order to make joints 110 and 120, three (3) different types of drills or cutting tools are required. Specifically, the tools required are as follows:
1. a first cutting bit for making holes 81 and 82 having cylindrical shaped cross sections, and oriented substantially perpendicular to the surface of the column; PA1 2. a second cutting bit for making the small width slots 112 and 122 extending from the holes 81 and 82, and the smaller width slots 112 and 122 are cut to have a first predetermined depth extending inwardly from the surface of the column; and PA1 3. a third cutting bit for making the larger width slots 113 and 123 extending from the holes 81 and 82, the larger width slots 113 and 114 are cut to have a second predetermined depth extending from the bottom of the smaller width groove further into the column.
As explained above, such drilling method requires three (3) different tools including a twist drill bit, a flat drill bit and a rotary side cutting bit. To make highly accurate holes and slots, it is required that the bits be change for each cut. This requires exact setting of the drill at appropriate marks as well as setting the exact moving distance and direction of the drill. Thus, the conventional method takes a significant amount of time, and is troublesome due to the requirement of exchanging the bits, and time and trouble associated with setting the drill for accuracy with each different bit.